"We are also protecting mosques, because there is always the concern of retaliatory crime or retaliatory incident," Kerlikowske said.

The suspect walked into the office building just after 4 p.m. Friday armed with a large caliber semi-automatic handgun and opened fire after asking for the manager, Kerlikowske said.

The shooter laid down his handgun and surrendered to SWAT officers about 12 minutes after the shooting began, Kerlikowske said.

The belief that it was a hate crime is based on what the suspect said to a 911 operator and supervisor when he took a phone from an office worker who called the emergency number. Kerlikowske would not say specifically what the man said.

All of the shooting victims -- including the one killed -- were women, he said. Most of the 18 people in the building were female, but there was no indication he was specifically targeting them, the chief said.

The wounded were taken to Seattle's Harborview Medical Center following the shooting, the hospital said. Three of them were in critical condition with injuries to their abdomens.

The other two victims were in satisfactory condition, the hospital said, including a 37-year-old woman who is 20 weeks pregnant. She was shot in the arm, while the other woman sustained a knee injury.

Assistant Police Chief Nick Metz said police had no specific information about any threats, but his department did issue an alert Thursday "reminding officers to be vigilant to monitor synagogues and mosques in the city."

Kerlikowske acknowledged that the suspect was a Muslim, but he did not reveal his name. He said there was no reason to believe more than one person was involved in the attack. Another law enforcement official told CNN the suspect was of Pakistani descent.

FBI Special Agent-in-Charge Laura Laughlin said the suspect was a U.S. citizen, not from Seattle.

Robert Jacobs, Pacific Northwest Regional director for the Anti-Defamation League, told CNN the group has been warning Jewish institutions to be wary and ensure they have adequate security because of the ongoing conflict in the Middle East. If they cannot, he said, it would be better for Jews "not to congregate in one location that might be an obvious site."